This aerial image provided by Tributary Environmental shows a home damaged by a landslide Friday, April 18, 2014, in Jackson, Wyo. / AP

by USA TODAY

by USA TODAY

JACKSON, Wyo. (AP) - A sudden lurch in a creeping landslide in the northwest Wyoming resort town of Jackson split a house in two and forced workers to abandon just-begun efforts to stabilize the hillside.

A huge crack in the ground that had opened up under the house a couple weeks ago shifted several feet downhill in less than a day, breaking off a room or two and leaving a door swinging above the precipice. Rocks and dirt tumbled down in an almost constant stream and a geologist warned much bigger chunks could fall. The ground had been moving at a rate of an inch a day.

"As it starts to get moving, it will start to get faster," George Machan, a landslide specialist consulting for the town, said at a town meeting Friday.

Still, Machan said the ground was unlikely to liquefy and collapse suddenly like the March 22 landslide in Oso, Wash., that killed 39 people.

More likely, large blocks of earth would tumble down piece by piece, he said, perpetuating the drawn-out threat to four homes on the hill and to two apartment buildings and four businesses below.

Town officials first noticed significant hill movement April 4. They evacuated 42 homes and apartment units April 9.

Between Thursday night and Friday morning, the shifting earth had bulged a road and a parking lot at the foot of the hill by as much as 10 feet. The groundswell pushed a small town water pump building 15 feet toward West Broadway, the town's main drag.

Efforts to slow the slide - such as pouring rock and dirt fill behind large, L-shaped concrete barriers arranged in a line at the base of the slide - were on hold to keep workers out of the danger zone.

"It's really not safe to put people out there. You try to do what you can, but at some point you're really restricted from entering the area," Machan said.

On a town webcam, pedestrians could be seen pausing in the rain now and then to gawk at the slide zone that's as big as three or four football fields. Cars and trucks on West Broadway also slowed occasionally, the cause of at least one fender-bender Friday and a police warning for lollygaggers.

On Monday, town officials lifted the evacuation for residents of about 30 homes outside the high-risk zone but said they couldn't drive on the neighborhood street. They've had to walk to and from home by cutting across private property.

On Friday, not even work crews could drive on Budge Drive, which was buckled several feet.

Town officials said they didn't know what was causing the slide but noted the area has seen considerable road-grading over the past few decades. The latest work was last year's construction of the Walgreens drug store, which opened in January.

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